Human Extinction 70,000 Years Ago: A Close Call

A report in the New York Times says that 70,000 years ago, the total human population may have dropped to as low as only 2,000 individuals!

What’s particularly interesting to me about this is the timing. About 50,000 years ago is regarded as the time when humans went through a major brain shift … ie, we got smarter. And it is widely known that evolution happens at a much faster rate in small isolated populations. Could the drop in population have contributed to a speeding up of our intellectual development?

Eastern Africa experienced a series of severe droughts between 135,000 and 90,000 years ago and the researchers said this climatological shift may have contributed to the population changes, dividing into small, isolated groups which developed independently.

Paleontologist Meave Leakey, a Genographic adviser, commented: ”Who would have thought that as recently as 70,000 years ago, extremes of climate had reduced our population to such small numbers that we were on the very edge of extinction.”

10 responses to “Human Extinction 70,000 Years Ago: A Close Call”

I’d take this “research” with a grain of salt. This is a “hypothesis” and one out of many. There’s also research that says that riding bicycles can give you cancer. What I’m trying to get across here is that this research should be severely questioned. I myself find it absurd.

This is interesting but I would like to or need to read more evidence and conclusion. In terms of rapid evolution — I have always read that “rapid” is not part of the process. We are evolving today but the end is a ways away. We have seen things like height increase, etc

Paperdreamer is right.
This new study is in line with the idea of Punctuated equilibrium which was put forward by Stephen J. Gould and Niles Eldredge. Basically the idea is that evolution is in fact not a process of slow gradual change, but rather is characterized by long periods of relative equilibrium (ie, little change is taking place within a species), followed by punctuations where a rapid change occurs. These rapid changes are generally thought to be caused by changing environmental conditions, or a drop off in population density, etc.

Something dramatic comes along and breaks the evolutionary silence, and all of a sudden we get major changes.

The Cambrian explosion is maybe the most vivid example of this. Seemingly out of nowhere, life went from being simple little multicellular organisms to a plethora of complex creatures. Very cool.